I always wondered why Hero decided, "Okay, he ruined my life on the day of my wedding and I had to go underground and pretend to be dead. Now, he wants me back, proved that the slander he spoke of me is wrong. LET'S GET MARRIED." What was influencing such (in my opinion) a tragic dicesion?

(I know the story is a comedy and the charecters are supposed to be married. But what are the reasons - from the storis point of view.)

Social standards back in the 16th century were much different to what they are now. Hero knew that her reputation was on the line as a innocent woman with her virginity. She knew that the only way to restore her position in society was to marry Claudio. If she hadn't, people could still see her as a man seeking maiden. Consider the quotation;

One Hero died defiled; but I do live,And surely as I live, I am a maid. (5.4.65-66)

This quote does indeed show that Hero was very relieved that Claudio still wanted to marry her, meaning her status and her image was protected. 'And sure as I live, I am a maid'. She is very relieved she still is a woman!